Abstract Tetrahydropyran-4-one and tetrahydrothiopyran-4-one derivatives with a 3-aryl substituent were synthesized by double-conjugate addition of water or H 2 S to divinyl ketones. These starting materials were prepared in two steps by conversion of lithiated α- bromostyrene derivatives with acrolein or cinnamaldehyde and subsequent oxidation of the divinyl alcohols with MnO 2. The electron-rich α-bromostyrene building blocks were ...